There is a conventional storage apparatus capable of preventing data loss at the time of power shutdown by physically separating a shared memory for storing and retaining control data from a cache memory for temporarily storing user data and by performing battery backup of the shared memory and the cache memory.
There is another storage apparatus that has a cache memory constituted from a volatile memory and a nonvolatile memory and can prevent loss of data stored in the volatile memory by saving data, which has been stored in the volatile memory, in the nonvolatile memory at the time of power shutdown (see, for example, Patent Literature 1).